Montelukast sodium (SINGULAIR®) is a leukotriene receptor antagonist approved for the treatment of asthma in adults and pediatric patients from 2 years old. The drug is currently being studied for the treatment of seasonal allergic rhinitis, as well as for potential use in children as young as 6 months old. Montelukast sodium is currently available as 10 mg film-coated tablets for adults and 4 mg and 5 mg chewable tablets for children.